Three-dimensional magnetic field support of blood pump rotors has been pursued as a means to produce next-generation rotodynamic pumps. Early designs were not completely successful, most probably due to a lack of sufficient stiffness in the suspension. However, newer designs have achieved some significant successes, and efforts are being undertaken to reduce the size and power consumption of these pumps. The specific aim of this Phase I project is to demonstrate, in a blood pump configuration, the feasibility of a magnetic bearing concept that can be used to develop more robust, higher reliability rotary blood pumping systems. The project will explore the effectiveness of implementing a self-regulating magnetic suspension based on a tuned inductance-capacitance-resistive electromagnetic (LCR-EM) circuit. Control of the levitation is essentially inherent in the construction of the circuit, and by the geometry and dynamic characteristics of the pump in which it is installed. Phase I will involve the analysis, design, fabrication, and test of a prototype blood pump that incorporates the LCR-EM circuit. Planned test activities include bench-top tests, submerged tests in various fluids, shock and vibration assessments, and mock loop tests. PROPOSED COMMERCIAL APPLICATIONS: Heart disease remains the leading cause of death and disability within the United States. Of the 200,000 Americans who die each year due to heart- related problems, about 30,000 to 60,000 could probably be saved with heart transplants. However, the shortage of donor hearts precludes this, and has stimulated the development of many mechanical heart assist and replacement devices. Should mechanical assist pumps prove sufficiently safe and reliable, the potential use to improve the quality of life for cardiac- impaired patients dramatically expands the market.